This invention relates generally to exercise machines for exercising a user's abdominal and back muscles. Exercise machines generally provide resistance to the movement of a user in order to strengthen muscles of the user's body. However, conventional techniques, such as sit-ups, crunches, or roman chair hyperextension exercises, use the body's own weight to exercise the abdominal and back muscles of the user. Consequently, the conventional techniques fail to provide support and controlled resistance to the movements of a user, which can be particularly problematic for out-of-shape or obese users. Specifically, conventional techniques lack ways to control the resistance and motion of the user to prevent injury from an uncontrolled movement or from overloaded and strained muscles.
Of the available exercise machines that may be used to exercise and strengthen a user's abdominal and back muscles by providing resistance to the user's movements, many only permit certain portions of the abdominal and back muscles to be exercised, which leaves other portions unexercised and typically uneven in strength. This often leads to injury. Furthermore, many of these machines do not support the user's back during the exercise, which may lead to hyperextension injuries. These exercise machines also may not be capable of adjusting the resistance to a user's movements or adjusting the position of the user to provide more difficult exercise routines. Additionally, many currently available exercise machines take up large amounts of usable space when not in use, which prevents them from being conveniently located in the user's residence.
Accordingly, a need exists for an exercise machine that permits the user to adjust for more or less difficulty during an exercise routine. A need exists for an exercise machine that supports the back to prevent injury and uncontrolled movements. Additionally, a need exists for an exercise machine that does not occupy an excessive amount of room when it is not in use and that permits easy and convenient storage. Further, a need exists for a foldable exercise machine that can be shipped fully-assembled in low-profile packaging to optimize shipping capacities and reduce shipping costs.